Triple world champion Niki Lauda has slammed Michael Schumacher's move on Rubens Barrichello at the Hungarian Grand Prix and labelled it "completely unacceptable".

The FIA stewards at the Hungaroring gave Schumacher a ten place penalty on the Spa-Francorchamps grid after investigating the incident.

"It was a hard fight, and this is what we are here for, but I accept that the FIA stewards saw it as too hard," said the Mercedes driver. And team boss Ross Brawn added: "We don't necessarily agree with their decision but we do accept the penalty."

Lauda said on RTL television: "To endanger another competitor in such a way is totally unnecessary. I cannot understand why he does those things."

He also commented on Sebastian Vettel's drive-through penalty that cost him victory in Hungary. Lauda believes the Red Bull driver should have immediately accepted the blame for falling too far behind the safety car, after initially gesticulating angrily from the cockpit and then explaining that he didn't know why he was penalised.

Vettel told reporters that he didn't see the safety car lights go out, and that his radio was intermittently not working during the race.

"It is important in such situations to say to yourself and everybody: I screwed up. End of story," said Lauda.